One Piece: Pirates Carnival Cheats on GameCube

By completing any Captain game or Straw Hat Member game in VS Mode, you will unlock voice data for that game's captain. Playing Luffy's game will give you Luffy's voice data, playing Kuro's game gives you Kuro's voice data, etc. You do not need to be the person playing the captain to unlock the data.

After getting the Grand Line 3 board. Go to Board Game then go to Password. Entered going left to right, and once you reach the 3rd column, go to the 2nd row. Enter the password X, A, A, Y, B, A, B, X, X.